GENETIC-VARIATION IN ASIATIC LIONS AND INDIAN TIGERS

Previous reports have suggested that Asiatic lions and tigers are high ly inbred and exhibit very low levels of genetic variation. Our analys es on these species have shown much higher degrees of polymorphism tha n reported. Randomly amplified polymorphic DNA (RAPD) analysis of 38 A siatic lions, which exist as a single population in the Gir Forest San ctuary in India, shows an average heterozygosity of 25.82% with four p rimers. Sperm motility studies by our colleagues corroborate this data . In Indian tigers, microsatellite analysis of five CA repeat loci and multilocus fingerprinting using Bkm 2(8) probe on a population of 22 individuals revealed a heterozygosity of 22.65%. Microsatellite analys is at loci Fca 77 and Fca 126 revealed polymorphism amongst the Asiati c X African lion hybrids, which has enabled us to use these as markers to discriminate the pure Asiatic lions from the hybrids. A similar an alysis was used to identify hybrids of Indian and Siberian tigers thro ugh polymerase chain reaction (PCR) amplification of hair samples. To ascertain the variation which existed before the population bottleneck at the turn of the present century, microsatellite analysis was perfo rmed on 50- to 125-year-old skin samples from museum specimens. Our re sults show similar levels of genetic variability as in the present pop ulation (21.01%). This suggests that low genetic variability may be th e characteristic feature of these species and not the result of intens ive inbreeding. DNA fingerprinting studies of Asiatic lions and tigers have helped in identifying individuals with high genetic variability which can be used for conservation breeding programs.